62 PRACTICAL FORESTRY 
floods have been produced by forest destruction, and 
where they have been lessened by the reboisement or 
reforestation of the mountains. 
A forest cover imparts regularity to the flow. 
Although the annual run-off may be the same in 
amount for the year from a forested or a deforested 
area, the flow from the forested area will be much 
more regular. There will be, in other words, less ex- 
tremely high and less extremely low water. ‘This is, 
however, to industrial establishments which may be 
located along and dependent upon such a stream, a 
matter of great importance. 
The destructiveness of floods is due more to the 
nature of the débris which they carry with them, 
than to the amount of water. When they are gentle 
in nature, and loaded only with silt, they are often 
of advantage. In the case of the Nile, for instance, 
flood-time is a great benefaction, because it moistens 
and covers the soil with a layer of fine, fertile mud. 
The alluvial lands along our great rivers are extreme- 
ly fertile, because they are formed of fine soil and hu- 
mus which have been washed from the higher lands. 
It is not these mild, benign floods which need be 
feared, but the sudden gushings of mountain tor- 
rents, in the checking of which the forest exercises 
a very decided influence. Even freshets do good 
sometimes. The stream-bed is often thus cleared of 
